Definition
A low-altitude airway in Alaska defined by non-directional radio beacons (NDBs) rather than VORs, identified by a color and a number (Green, Red, Amber, or Blue, e.g., G7, R5, A2, B3). Green and Red airways run east-west; Amber and Blue airways run north-south. They appear on IFR en route low altitude charts as part of the federal airway system.
Plain English
An older type of low-altitude airway, still used in Alaska, that follows a path between NDB radio beacons. Each one has a color name and a number. The colors tell you which direction the airway runs.
Context Anchor
Seen on IFR en route low altitude charts, especially in areas where older beacon-based routes are still published.
Derivation
The 'colored' name comes from the original 1930s U.S. airway system, when airways were drawn on charts in different colors to show direction of travel. Most of the lower 48 states transitioned to VOR-based 'Victor' airways, but the original color-coded NDB airways remain in use in Alaska.
Why Pilots Care
If you fly IFR in Alaska, you will file and fly colored airways, and you need to know that the color tells you orientation (east-west vs. north-south) and that navigation is by NDB rather than VOR. Mistaking one for a Victor airway can lead to using the wrong navigation equipment or misreading the chart.
Intuition Check
Do not read colored airway as a route that is physically colored in the sky or simply drawn in color on the chart. In this FAA context, the color is part of the airway’s official route designation.
Example Sentence 1
The flight plan routed us along Green 7, a colored airway between two NDBs in southeast Alaska.
Example Sentence 2
During preflight planning the instructor pointed out the colored airway options available below 18,000 feet.